Brake for elevators



(No Model.) 4 A C. J. UNDERWOOD.

Brake forElevators. No. 243,013. Patented June 104,1881.

N. PETERS. moumgnpm, Nmingm. DJ;

UNITED STATES.

PATENT OFFICE. i

CHARLES J. UNDERWOOD, OF BOSTON, MASSACHUSETTS.

BRAKE FOR ELEVATO RS.

SPECIFICATION forming part of Letters Patent No. 243,013, dated June 14,1881.

-pplication filed April 19, 1881. (No model.)

WOOD, of Boston, in the county of Suolk and State of Massachusetts, haveinvented certain new and usefulrlmprovements in Brakes forl` Elevators,of which the following is a full,`

clear, and exact description.

The purpose of this invention is to provide an attachment to elevators,so that in caseof accident from the breakage of the rope or other causewhich would leave the platform or carriage of the elevator free to fall,such fall of the elevator would be automatically arrested, andpreferably in a manner to secure the utmost safety in the furtherdownward movement of the elevator by regulating and graduating' thespeed thereof. 4

The invention, as to this purpose, consists,in substance,of anarrangement of wei gh ted levers or other equivalent levers havingshoes, and severally suspended by cordsfrom the elevator-rope,incombination with a post or posts and an elevator carriage or platform,all substantially as hereinafter described.

In the accompanying plate of drawings,Fig ure lis a view ofan elevatorwith some parts in vertical section, illustrating the safety attachmentof this invention as outof action 5 and-Fig. 2 is a view illustratingthe safety attachment as in action. Fig. 3 is a plan view. Fig. 4 is anelevator with the elevator-carriage partly broken out. Fig. 5 is asectional view of details.

In the drawings, A represents the carriage or platform of an elevatorsuspended from a hoisting-rope,B, and constructed and arranged to moveup and down between suitable stationary guide-posts, C, on oppositesides, and upon guide-anges thereof, all substantially as ordinarily,and therefore needing no more particular description herein.

D E are the opposite sides of lthe elevatorp carriage, which at each ofthe posts C carries shoe is duplicated at each side of the elevator, andin such duplication the shoes lie directly opposite to each other andhave their bearingsurfaces (l located upon opposite sides of theguide-post. Each weighted and shoe lever is suspended from a rope, f,and these several ropes are connected to a common collar, J, whichloosely surrounds the elevator-rope B above the carriage A, and thisloose collar J is fastened toa fixed collar, K, which is upon the rope Aabove the loose collar J, by a pin, g, which is rigidly attached to thesaid loose collar, and is secured to the said fixed collar by a pin, h,that passes through it and rests upon the upper side of the fixedcollar, and thus the said loose collar, with its suspended levers F, iscarried up and down in the usual upward and downward travel of thecarriage. The holdingpin h is adapted by a cord, l, attached to it andto an angular lever, m, connected to a cord, n, to be withdrawn from ping of the' stationary collar K, when so desired, by the attendant uponthe elevator-carriage.

Each'weighted lever F carries a pawl, o, in position to engage with theteeth of a ratchetrail, p, of the elevator, and these pawls andratchet-rails are severally arranged to allow the levers, as to them, tomove downward, but to prevent their upward movement. Thesuspension-ropes for the levers are of sufficient strength only tosupport the weight of the levers. A severing of the ropes f, by whichthe levers F are suspended, or their release in any other wa-y fromtheir support upon the elevator-rope, leaves them free to fall under theaction of their weighted ends, and thus the shoes, by their surfaces d,are brought into contact with the guide-posts, and the force of thiscontact obviously will be in direct proportion to the-weight of thelevers and the leverage otherwise exerted by them. As these levers arearranged as herein described, a severing of their suspendin g-ropesoccurs, provided the elevator-rope breaks below the position of theloose collar upon the elevator-rope, and thus they are left free to thencome into contact by their shoes with the sides of the guideposts; andin case the elevator-rope breaks 4above its fixed collar K, or itstension is there otherwise released, then` the levers are free to dropand come by their shoes into the contact described. Again, this contactof the shoes is- IOO placed. within the control of the attendant uponthe elevator through the cords /L Z and lever m, as above described.

From thisdescription it is plain that the levers and their shoes willact, when placed at their bearings upon the guide-posts, according totheir leverage and weight, as a stop to the downward travel of theelevator, and thus obviously, under a proper weighting of the same, theyare capable of securing the full stop ofthe elevator in such movement,or such an arrest of the same as to allow the elevator to fall andcontinue slowly and gradually in its downward movement without fullyarresting it, and it is preferable to arrange them so as to actsubstantially in this manner. The fall of the weighted levers is insuredbecause of the pawl o and ratchet p connection between them and theelevator, as has been described, which holds them from jumping up orlifting.

llo steady the movement of the levers F guides are provided, as shown atq.

It is plain that each lever, through its shoe, when in operation, has athrust against its side of the guide-post, and that the thrust of eachis met by a corresponding thrust directly upon the opposite side of thesanne post by another lever and its shoe there arranged. This preventsany twisting or bending of the guideposts when the levers are inoperation, and in this respect this invention differs from many oftheother safety attachments, which, as heretofore constructed and arranged,act against the guide-posts in a direction and in a manner to thrust orthrow them out of their true position.

The posts G may be the guide-posts of the elevator or separate anddistinct posts therefrom, and as to the levers F, their operation,herein described, may be similarly secured by springs, in lieu of byweights, the springs being suitably applied therefor.

Having thus described my invention, what I claim, and desire to secureby Letters Patent,

1. ln an elevator, the combination, with the posts C, theelevator-carriage, and the hoisting rope or cable, of loose levers F,weighted at their outer ends, and provided with brakeshoes H, attachedat or near their center directly to the inner ends of said levers, andcords f, attached to the weighted ends of the levers and to thehoisting-rope, substantially as shown. and described, whereby thebrakeshoes are adapted to act upon the posts by the direct inwardpressure of the lever without the intervention of wedges to force thebrakeshoes on the posts, as set forth.

2. The levers F, having brake-shoes H and ropes f, suspendin gthem fromthe elevator-rope B, and pawl o and ratchet p, in combination with theposts G and an elevator carriage or platform, all substantially asdescribed, for the purpose speciiied.

3. The levers F, having brakeshoes H and ropes f, suspending them fromthe elevator-rope B through a loose collar, J, and xed collar K, incombination with the posts C and an elevator-carriage, all substantiallyas described, for the purpose specified.

4. The levers F, having brake-shoes H and ropes f, suspending` them fromthe elevator-rope through a loose collar, J, and xed collar K, connectedtogether by a pin, g, having a detachable holding-pin, h, in combinationwith the posts C and an elevator carriage or platform, all substantiallyas described, for the several purposes specified. f

In testimony whereof 1 have hereunto set my hand in the presence of twosubscribing witnesses.

CHARLES J. UNDERWOOD.

Witnesses:

EDWIN W. BROWN, WM. S. BELLows.

